Dam



Feb. 23, 1954 E. FREYSSINET DAM Filed June 29, 1948 Patented Feb. 23, 1954 UNITED STATES PATENT OFFICE DAM Eugene Freyssinet, Ncuilly-sur- S eine, France Application June 29, 1948-, Serial No. 35,785 Claims priority, applicationFrance July 4; 1947 (o1. ti-30) Claims. t 1 t This invention relates to dam structures particularly designed for use under conditions considered as poor or even detrimental to conventional dams.

A firstobject of my invention consists ina considerable reduction inthe mass of concrete required for executing the dam.

A further object of the invention is to ensure a stability of the dam that is completely independent of the weight of concrete forming it.

A further object of the invention is to provide a greater adaptability in the general shape of the work so as to allow often a better use of the shape and properties of the ground and in practice the execution of dams on any ground whatever. A further object of the invention is the constitution of dams by means of small s'zed elements executed outside the final location of the work, said elements being transported and assembled together subsequently.

Another object of the invention is to provide a dam structure so designed that a. The weight of a mass of Water as large as may be desired cooperates in the stability of the dam.

b. The volume of the concrete portion of the work is no longer defined by conditions of gravity and general stability but only by conditions of resistance to breaking.

0. By reason of the advantage a, the horizontal straining on the ground may be reduced as much as desired which allows setting a dam on extremely poor ground in particular on permeable alluvial ground.

d. Dams may be made that include only stretched members constituted by concrete submitted to a preliminary stress in two directions and bound in a third direction and which are consequently both plastic and highly shock-resisting.

In the accompanying drawing:

Figure l is a diagrammatic vertical section of a dam according to the invention;

Figure 2 shows, on an enlarged scale, a modifled portion of this dam.

The dam shown in Figure 1 comprises a head water wall 3 which closes the valley and is integral with a bottom slab 2 which forms a floor lying on its upstream side and resting freely on the ground; said slab extends through a curved portion I at its front or upstream end. The connection between the wall 3 and the slab 2 forms an acute angular edge portion l1 and this connection is furthered by one or more connecting members 4.

This dam is adapted to be constructed on poor ground which is generally formed by an. alluvial layer 15 which is often not very thick andwhich covers solid subsoil [6 usually formed of rocks in which strong foundations can be built.

The edge port'on ll rests on a foundation 18 through the agency of a pivoting link 19. The latter includes a mass of concrete of restricted cross-sectional area reinforced with armatures 84 passing through said narrow cross-section along its medial line. The foundation block 18 rests on the subsoil through corrugated or angular portions whereby it may resist oblique stresses directed downstream.

The foundation block 18 is formed in a suitably shaped excavation the depth of which is such that it reaches the resisting subsoil. It may occur that such an excavation leads to very important transfers of earth. In this case, as illustrated in Fig. 2, it is possible to replace the foundation T8 at least partly by piles that are driven in obliquely until they reach the resistant subsoil.

These piles, the number. size, and slope of which are selected in accordance with the stresses to be borne are capped by an elongated solid mass 8| extending parallel to the end face of the nose or annular edge portion 82 which bears on said solid mass through the agency of the pivoting link 79 and the fiat jacks 83. These jacks allow adjusting the reaction of the foundation on the nose of the dam.

The presence of a foundation for bearing the nose of the work allows on one hand a reduction in the upstream extension of the floor 2 and on the other a shifting of the closing wall 3 towards verticality.

The front part of floor or bottom slab 2 is constituted by a solid mass of concrete 96 anchored in the resistant subsoil and connected with the floor 2 through a vault-shaped slab H1 in which the plane defining the beginning of the vaulted part is substantially vertical in alignment with the mass 96 while it is connected without any gap with the floor 2.

By providing such an arcuate slab obtained by means of concrete submitted to a preliminary stress, it is possible to admit for the latter important deformations in all directions without its watertightness being impaired. It is possible to prevent any local substantial deformation of the slab by means of ribs 98. Moreover it is of advantage to provide the mass 9'6 with a visiting gallery in the inside thereof as shown at 99 which gallery is also adapted to collect the infiltration water.

What I claim is:

1. A dam comprising a head water wall, a bottom slab integral with said wall on its upstream side and resting freely on the ground, the connection between said wall and said slab forming an acute angular edge portion, and an oblique abutment structure anchored in the ground against downstream displacement and bearing against said angular edge portion, on the downstream side thereof.

2. A dam comprising a head water wall, a bottom slab integral with said wall on its upstream side and resting freely on the ground, the connection between said wall and said slab forming an acute angular edge portion, an oblique abutment structure anchored in the ground against downstream displacement and bearing against said angular edge portion, on the downstream side thereof, and hinge means between said abutment structure and said angular edge portion for allowing slight angular displacement of said edge portion relatively to said abutment structure.

3. A dam as claimed in claim 2, wherein the hinge means includes a reinforced concrete link having a restricted cross-section.

4. A dam as claimed in claim 2, wherein the hinge means connects the abutment structure to a part of the angular edge portion capable of slight displacement relatively thereto and spaced therefrom, an elongated flat, jack being inserted in the space between said part and the edge portion.

5. A dam as claimed in claim 2, standing on a ground with solid subsoil, further comprising a flexible, downwardly curved, upstream extension integral with the bottom slab and ending in the subsoil, said extension as wall as the abutment structure being anchored therein.

EUGENE FREYSSINET.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 764,916 Church July 12, 1904 1,010,254 Greathead Nov. 28, 1911 1,736,939 Probst Nov. 26, 1929 FOREIGN PATENTS Number Country Date 3,423 Netherlands of 1919 708,568 France of 1931 

